Method for establishing device-to-device communication

ABSTRACT

A method and system establishes a peer-to-peer (P2P) communication session between user equipments (UEs) under control of a network. A proximity services (ProSe) server associated with a first controlling network receives from a first UE a communication request message indicating that at least one other UE is in close proximity with the first UE. Based on the close proximity between the UEs, the server establishes a P2P group which includes the first UE and at least one other UE. In addition, the server identifies respective P2P Internet Protocol (IP) addresses for the UEs within the established P2P group. The server then instructs the UEs to communicate within the established P2P group using respective P2P IP addresses. Following receipt of a response indicating acceptance by a second UE of an instruction to communicate within the established P2P group using a corresponding P2P IP address, the server establishes the communication session.

BACKGROUND

1. Technical Field

The present disclosure relates in general to wireless communicationdevices and in particular to direct communication between wirelesscommunication devices.

2. Description of the Related Art

Conventional methods for establishing peer-to-peer (P2P) communicationbetween two wireless communication devices or user equipment (UE) areautonomously executed by the devices. P2P communication can be providedusing Bluetooth and WiFi Direct as well as other close rangecommunication technologies. In the WiFi Direct case, for example,devices execute discovery procedures to discover other devices in closeproximity and, when other devices are discovered, the devices executeprocedures for forming a P2P group. In addition, at least one deviceassigns IP addresses to each device in the P2P group. All theseprocedures are autonomously executed by the P2P devices without thenetwork being able to control these procedures and/or control theestablishment of P2P groups in any way. As a result, the network isunable to control or manage the establishment of P2P groups and/orcharge a subscriber for providing or facilitating direct communicationservices.

BRIEF DESCRIPTION OF THE DRAWINGS

The described embodiments are to be read in conjunction with theaccompanying drawings, wherein:

FIG. 1 is a system diagram illustrating an environment in which a firstwireless communication device can be configured to operate as an accesspoint for an established peer-to-peer (P2P) group via a proximityservices server, according to one or more aspects of the disclosure;

FIG. 2 provides a block diagram representation of a proximity servicesserver, within which the various features of the described embodimentscan be advantageously implemented, according to one embodiment;

FIG. 3 illustrates a first messaging sequence used to establish a P2Pgroup and enable a P2P communication session, according to oneembodiment;

FIG. 4 illustrates a second messaging sequence used to establish a P2Pgroup and enable a P2P communication session, according to oneembodiment;

FIG. 5 illustrates a third messaging sequence used to establish a P2Pgroup and enable a P2P communication session, according to oneembodiment;

FIG. 6 illustrates a fourth messaging sequence used to establish a P2Pgroup and enable a P2P communication session, according to oneembodiment;

FIG. 7 is a flow chart illustrating one method for establishing a P2Pgroup and enabling a P2P communication session, according to oneembodiment;

FIG. 8 is a flow chart illustrating a second method for establishing aP2P group and enabling a P2P communication session, according to oneembodiment;

FIG. 9 is a flow chart illustrating a third method for establishing aP2P group and enabling a P2P communication session, according to oneembodiment; and

FIG. 10 is a flow chart illustrating a fourth method for establishing aP2P group and enabling a P2P communication session, according to oneembodiment.

DETAILED DESCRIPTION

The illustrative embodiments provide a method and system forestablishing a peer-to-peer (P2P) communication session between userequipments (UEs) under control of a network. A proximity services(ProSe) server associated with a first controlling network receives froma first UE that is communicatively coupled to the first controllingnetwork a communication request message indicating that at least oneother UE is in close proximity with the first UE. Based on the closeproximity between the UEs, the server establishes a P2P group whichincludes the first UE and at least one other UE. In addition, the serveridentifies respective P2P Internet Protocol (IP) addresses for the UEswithin the established P2P group. The server then instructs the UEs tocommunicate within the established P2P group using respective P2P IPaddresses. Following receipt of a response indicating acceptance by asecond UE of an instruction to communicate within the established P2Pgroup using a corresponding P2P IP address, the server establishes thecommunication session.

In the following detailed description of exemplary embodiments of thedisclosure, specific exemplary embodiments in which the various aspectsof the disclosure may be practiced are described in sufficient detail toenable those skilled in the art to practice the invention, and it is tobe understood that other embodiments may be utilized and that logical,architectural, programmatic, mechanical, electrical and other changesmay be made without departing from the spirit or scope of the presentdisclosure. The following detailed description is, therefore, not to betaken in a limiting sense, and the scope of the present disclosure isdefined by the appended claims and equivalents thereof.

Within the descriptions of the different views of the figures, similarelements are provided similar names and reference numerals as those ofthe previous figure(s). The specific numerals assigned to the elementsare provided solely to aid in the description and are not meant to implyany limitations (structural or functional or otherwise) on the describedembodiment.

It is understood that the use of specific component, device and/orparameter names, such as those of the executing utility, logic, and/orfirmware described herein, are for example only and not meant to implyany limitations on the described embodiments. The embodiments may thusbe described with different nomenclature and/or terminology utilized todescribe the components, devices, parameters, methods and/or functionsherein, without limitation. References to any specific protocol orproprietary name in describing one or more elements, features orconcepts of the embodiments are provided solely as examples of oneimplementation, and such references do not limit the extension of theclaimed embodiments to embodiments in which different element, feature,protocol, or concept names are utilized. Thus, each term utilized hereinis to be given its broadest interpretation given the context in whichthat terms is utilized.

As further described below, implementation of the functional features ofthe disclosure described herein is provided within processing devicesand/or structures and can involve use of a combination of hardware,firmware, as well as several software-level constructs (e.g., programcode and/or program instructions and/or pseudo-code) that execute toprovide a specific utility for the device or a specific functionallogic. The presented figures illustrate both hardware components andsoftware and/or logic components.

Those of ordinary skill in the art will appreciate that the hardwarecomponents and basic configurations depicted in the figures may vary.The illustrative components are not intended to be exhaustive, butrather are representative to highlight essential components that areutilized to implement aspects of the described embodiments. For example,other devices/components may be used in addition to or in place of thehardware and/or firmware depicted. The depicted example is not meant toimply architectural or other limitations with respect to the presentlydescribed embodiments and/or the general invention.

The description of the illustrative embodiments can be read inconjunction with the accompanying figures. It will be appreciated thatfor simplicity and clarity of illustration, elements illustrated in thefigures have not necessarily been drawn to scale. For example, thedimensions of some of the elements are exaggerated relative to otherelements. Embodiments incorporating teachings of the present disclosureare shown and described with respect to the figures presented herein.

FIG. 1 is a system diagram illustrating the overall environment in whicha first wireless communication device or first user equipment (UE) canbe configured to operate as an access point for an establishedpeer-to-peer (P2P) group via a proximity services server, according toone or more aspects of the disclosure. Environment 100 comprises firstuser equipment (UE) 104 and second UE 106. Environment 100 alsocomprises first controlling network 110 on which both first UE 104 andthird UE 108 are subscribers that are both wirelessly connected toeNodeB 111. Also included within environment 100 is second controllingnetwork 130 on which second UE 106 is a subscriber that is wirelesslyconnected to eNodeB 131.

First controlling network 110 comprises evolved Node B (eNodeB) 111 andEvolved Packet Core (EPC) 112. EPC 112 includes Mobility ManagementEntity (MME) 114, which is the key control node for a Long TermEvolution (LTE) access-network. Also included within first controllingnetwork 110 are an Internet Protocol Multimedia Subsystem (IMS) network,the Internet, and a fixed IP network collectively illustrated asIMS/Internet/Fixed IP network 120. As illustrated, IMS/Internet/Fixed IPnetwork 120 comprises first proximity services (ProSe) server 122 andfirst IMS server 124. First ProSe server 122 is also referred to asfirst server 122 herein.

Similarly configured to first controlling network 110, secondcontrolling network 130 comprises enodeB 131 and Evolved Packet Core(EPC) 132, which includes Mobility Management Entity (MME) 134. Alsoincluded within second controlling network 130 are IMS/Internet/Fixed IPnetwork 140, which includes second proximity services (ProSe) server 142and second IMS server 144.

In order to establish a peer-to-peer (P2P) group (e.g., P2P group 102which can be considered to be a direct communication network) and acorresponding P2P communication session for wireless communicationdevices under control of a network, first (ProSe) server 122 associatedwith first controlling network 110 transmits a request for establishingthe P2P group to first UE 104, which is communicatively coupled to firstcontrolling network 110. In one embodiment, the procedure forestablishing the P2P group is initiated or triggered when first UE 104discovers second UE 106. In particular, first UE 104 can discover secondUE 106 using one of a number of close range communication technologies,including but not limited to (a) WiFi Direct (b) LTE Direct and (c)Bluetooth. Following discovery of second UE 106, first UE 104 sends acommunication request to first controlling network 110 and specificallyto first server 122 requesting establishment of a session with second UE106. For example, in one implementation, first UE 104 sends a SessionInitiation Protocol (SIP) Invite request (message) to first server 122to trigger first server 122 to establish P2P group 102. The receipt ofan SIP Invite request from first UE 104 informs first server 122 thatthe target device (second UE 106) is located within close proximity tothe requesting device (first UE 104).

Based on the close proximity of first UE 104 to second UE 106, firstserver 122 makes a determination to establish the session beingrequested directly between first UE 104 and second UE 106. In otherwords, first server 122 decides to establish a direct userdevice-to-user device communication channel or direct (P2P)communication network to enable a direct communication session betweenfirst UE 104 and second UE 106. By establishing the direct user-plane,first server 122 reduces network traffic and potentially improves theuser experience by offering reduced round-trip delay. This reduction inround trip delay is particularly useful in a number of applicationsincluding, for example, gaming applications.

First server 122 initiates a P2P group formation procedure during whichfirst server 122 provides configuration data to both first UE 104 andsecond UE 106 to enable the two UEs to form a P2P group using P2Pprocedures, as described herein. After forming the P2P group, a specificclose range communication technology is identified and/or selected forthe P2P group communication. Thus, for example, first server 122 canselect WiFi as the close range communication technology for the P2Pgroup communication once it is determined or confirmed that the two UEssupport WiFi. First server 122 also assigns specific IP addresses torespective WiFi interfaces of the two user devices. As a result, firstUE 104 and second UE 106 will be able to participate in a directcommunication session using the assigned IP addresses. Within thedescriptions which follow, these assigned IP addresses are also referredto as the assigned P2P IP addresses.

With the P2P group setup completed, first server 122 responds to thecommunication request sent by first UE 104 by inviting the two UEs(i.e., first UE 104 and second UE 106) to establish the requestedcommunication session over the established P2P group. The two UEs canthen initiate direct communication with each other within an establishedP2P group 102 in which first UE 104 is a group owner operating as anaccess point (AP) for the P2P group and second UE 106 operates as a P2Pclient. By operating as an AP, first UE 104 transmits Beacons with theP2P IP and accepts associations from other P2P devices or legacy WiFidevices (i.e., UEs that do not implement P2P functionality).

With specific reference now to FIG. 2, there is depicted a block diagramrepresentation of an example proximity services (ProSe) server, withinwhich the various features of the described embodiments can beadvantageously implemented, according to one embodiment. First (ProSe)server 122 includes one or more processor(s) 202 coupled to systemmemory 206 via system interconnect 204. As shown, system memory 206 caninclude therein a plurality of processor-executable modules, includingoperating system (O/S) 208, IMS application 212, and P2P group set-uputility 216. In addition, system memory 206 includes peer-to-peer (P2P)group operating parameters 210, and P2P IP addresses 211. The varioussoftware and/or firmware modules have varying functionality when theircorresponding program code is executed by processor(s) 202 or otherprocessing devices within first ProSe server 122.

In one embodiment, P2P operating parameters and channel 210 comprise (i)a preferred close range wireless communication technology (e.g., WiFiDirect or LTE Direct) that can be used for setting up a P2P group, (ii)a Service Set Identifier (SSID) to publicly identify the P2P networkgroup, (iii) a secret key to be used by first UE 104 and second UE 106to secure direct communication between first UE 104 and second UE 106,(iv) a preferred operating wireless channel for the P2P group and (v)P2P IP addresses assigned to first UE 104 and second UE 106,respectively, and to other UEs within P2P group.

As illustrated, first ProSe server 122 can further include one or moreinput/output (I/O) controllers 220 which support connection to andprocessing of signals from one or more connected input device(s) 222,such as a keyboard, mouse, touch screen, or microphone. I/O controllers220 also support connection to and forwarding of output signals to oneor more connected output device(s) 224, such as a monitor or displaydevice or audio speaker(s). In addition, server 122 includes one or moredevice interface(s) 228, which can provide an integration point forconnecting other device(s) to server 122. In one implementation, server122 connects to IMS server 124 using device interface(s) 228.

First ProSe server 122 comprises a network interface device (NID) 232.NID 232 enables server 122 to communicate and/or interface with otherdevices, services, and components that are located external to server122. These devices, services, and components can interface with server122 via an external network, such as network 236, using one or morecommunication protocols. In particular, in one implementation, server122 uses NID 232 to connect to IMS server 124 via an external network,such as network 236. As illustrated, IMS server 124 comprises SIPrequest 240 and IMS stack 244.

The connection to and/or between network 236 and server 122 can be wiredor wireless or a combination thereof. For purposes of discussion,network 236 is indicated as a single collective component forsimplicity. However, it is appreciated that network 236 can comprise oneor more direct connections and/or indirect or wireless connections toother devices as well as a more complex set of interconnections as canexist within a wide area network, such as the Internet.

Also illustrated in FIG. 2 is UE communication network 234 by whichfirst ProSe server 122 is communicatively connected to at least one UEor wireless communication device, including first UE 104. UEcommunication network 234 can comprise a wireless network and one ormore wired networks including direct connections to other devices withinfirst controlling network 110 (FIG. 1).

The various components within first ProSe server 122 can be electricallyand/or communicatively coupled together as illustrated in FIG. 2. Asutilized herein, the term “communicatively coupled” means thatinformation signals are transmissible through various interconnectionsbetween the components. The interconnections between the components canbe direct interconnections that include conductive transmission media,or may be indirect interconnections that include one or moreintermediate electrical components. Although certain directinterconnections are illustrated in FIG. 2, it is to be understood thatmore, fewer or different interconnections may be present in otherembodiments.

FIG. 3 illustrates a first messaging sequence used to establish a P2Pgroup and enable a P2P communication session, according to oneembodiment. In first message sequence 300, each message is numbered, andthe messages range from message 1 to message 6e. Also, the functionalprocesses at the different devices are illustrated as numbered blocks(e.g., 305). First UE is identified as belonging to user Adam, whilesecond UE is identified as belonging to user George. As shown at block305, first (ProSe) server (A) 122 associated with first controllingnetwork 110 decides to form a P2P group between first UE 104 and secondUE 106. First ProSe server 122 transmits a request (i.e., message 1) forestablishing the P2P group to first UE 104 which is communicativelycoupled to first controlling network 110. In one embodiment, firstserver 122 decides to initiate a P2P group formation between first UE(“Adam”) 104 and second UE (“George”) 106 independent of (i.e., withoutrequiring) an initial communication request from first UE 104 toinitiate or establish a P2P group or P2P communication session. In thiscase, first server 122 can request that first UE send a subsequentcommunication request in a specific format (e.g., using an SIP request).In one or more alternate embodiments (as shown in FIGS. 4-6, describedhereafter), first server 122 is triggered to initiate a P2P groupformation between first UE 104 and second UE (“George”) 106 followingreceipt of a communication request sent by first UE 104 requesting acommunication session with second UE 106. From a communication requestreceived from first UE 104 or by another proximity determination made atfirst server 122, server 122 receives an indication or determines thatfirst UE 104 and second UE 106 are in close proximity (of each other),such that direct communication can be established between first UE 104and second UE 106.

As previously described, first server 122 initiates the P2P groupformation by sending a ProSe group setup request message (i.e.,message 1) to first UE 104. The group setup request message includes anumber of P2P group operating parameters 210 including a Modeinformation element that indicates the specific close rangecommunication technology (e.g., WiFi Direct or LTE Direct) to use forsetting up the P2P group. In addition to selecting a specific closerange communication technology (e.g., WiFi Direct) for the P2P group,first server 122 also provides, within the operating parameters, thefollowing information elements:

(a) an SSID to use for WiFi Direct operation, where the SSID iscompliant with the WiFi P2P specification and is in the form“DIRECT-xy”, where xy are two random characters;

(b) a WiFi Secret Key to be used by both first UE 104 and second UE 106(as the Pairwise Master Key (PMK)) to secure the WiFi directcommunication;

(c) Implement Group Owner, which if set, serves to instruct first UE 104to implement a Group Owner (GO) functionality specified in the WiFi P2Pspecification. By implementing the GO functionality, first UE 104essentially becomes an access point (AP) that transmits Beacons with theP2P IP and accepts associations from other P2P devices or legacy WiFidevices (i.e., UEs that do not implement P2P functionality). If the“Implement Group Owner” parameter value is not set, the parameter valueserves to instruct a UE receiving this parameter configuration tooperate as a P2P client that attempts to discover and associate with aGO; and

(d) Accept P2P Device ID parameter value, which is only required whenthe Implement Group Owner is set and indicates from which P2P device theGO (e.g., first UE 104) should accept WiFi association requests.Association requests from P2P devices that do not provide the Accept P2PDevice ID parameter value are rejected by the GO.

In response to the group setup request (message 1), first UE 104responds with a ProSe Group Setup Response message (i.e., message 2)which includes (a) the WiFi channel on which first UE 104 startsoperating as the GO and (b) the respective P2P IP addresses (i.e., IPaddress A and IP address B) assigned to first UE 104 and second UE 106.In one embodiment, these P2P IP addresses are allocated by first UE 104in order to expedite the P2P group formation by eliminating the need tosubsequently use the Dynamic Host Configuration Protocol (DHCP) by whichIP addresses can be automatically provided. The Dynamic HostConfiguration Protocol (DHCP) is a network protocol used to configuredevices that are connected to a network (e.g., a P2P group or network)so the devices can communicate on that network using the InternetProtocol (IP). The WiFi P2P specification assumes that a GO functions asa DHCP server and dynamically allocates IP addresses to P2P clients.However, this DHCP functionality is not required in the disclosed P2Pgroup formation procedure.

By having first UE 104 send the assigned P2P IP addresses to firstserver 122, first server 122 is able to subsequently invite first UE 104and second UE 106 to establish a direct communication session by usingthese assigned P2P IP addresses.

At block 310, first UE 104 activates the WiFi by tuning to the indicatedWiFi channel (e.g., channel 11) and beginning to function as the GO, inwhich role first UE 104 essentially becomes an AP. In one embodiment,first UE 104 tunes to the indicated WiFi channel and/or begins operatingas the GO by transmitting and/or receiving one or more signals ormessages (e.g., messages 3). As the GO, first UE 104 accept associationsonly from a WiFi client that includes in the Association Request a P2PDevice ID=Accept P2P Device ID, in order to ensure that only the UEsthat first server 122 has previously identified for inclusion within theP2P group can be part of the established P2P group.

Following, or concurrently with WiFi activation by first UE 104, firstserver 122 sends a ProSe Group Setup Request (i.e., message 4) to secondUE 106 via second ProSe server 142. This request needs to be routed viaanother ProSe server if second UE 106 is unknown to first server 122.For example, when second UE 106 has a proximity services subscription inanother mobile network, such as second controlling network 130, therequest is routed through second server 142. In one implementation,first server 122 is able to find the contact information of secondserver 142 (i.e., ProSe Server B) by performing a Domain Name System(DNS) query or by querying the Home Subscriber Server (HSS) of second UE106. It is assumed that, with the described embodiments, first server122 knows the ProSe identity of first UE 104 (e.g.prose1234@operator1.com) and second UE 106 (e.g.prose5678@operator2.com).

The ProSe Group Setup Request (message 4) sent to second UE 106 includesthe P2P operating parameters including the same Mode information sentpreviously to first UE 104. When Mode=WiFi Direct, the followinginformation elements are also included:

-   -   a. The SSID: The same SSID sent to first UE 104.    -   b. The WiFi Secret Key: The same pre-shared key sent to first UE        104.    -   c. The WiFi Channel: The WiFi channel indicated by first UE 104        (via message 2).    -   d. IP Address B: a second assigned P2P IP address previously        allocated by first UE 104.    -   e. Implement Group Owner: In this case, this parameter value is        unset so that second UE 106 behaves as a P2P client that        attempts to discover and associate with a GO (e.g., first UE        104).    -   f. P2P Device ID: The same as the Accept P2P Device ID        previously sent to first UE 104 (via message 2).

Second UE 106 accepts the request and responds with a ProSe Group SetupResponse (i.e., message 5) which is forwarded to first ProSe Server (A)122. Second UE 106 starts functioning as P2P client and searches for aGO supporting the received SSID. Thus, second UE 106 sends a ProbeRequest (as per the WiFi P2P specs) illustrated as message/signal 6awhich includes the SSID and the P2P Device ID received from the network(via message 4). First UE 104 responds via message/signal 6b to theProbe Request since the probe request contains a P2P Device ID thatmatches the Accept P2P Device ID received from first server 122.

Following the response by first UE 104 to the probe request, (a) anauthentication procedure (i.e., via message 6c) such as IEEE 802.11authentication and (b) an association procedure (i.e., via message 6d)are performed between the two devices. The authentication andassociation procedures are followed by a handshake procedure (i.e., viamessage 6e), such as 802.1x 4-way handshake. The association request(i.e., message 6d) sent by first UE 104 includes the P2P Device ID(provided by message 1 and) received by first server 122 and firstcontrolling network 110. During the 4-way handshake procedure, first UE104 and second UE 106 use the shared WiFi secret key to derive keyingmaterial for protecting unicast and broadcast traffic (as per IEEE802.11e specifications). At block 315, first UE 104 assigns the first IPaddress to the established WiFi interface, and at block 320, second UE106 assigns the second IP address to the established WiFi interface atthe second UE 106.

FIG. 4 illustrates a second messaging sequence used to establish a P2Pgroup and enable a P2P communication session, according to oneembodiment. Message sequence 400 illustrates a device initiated requestfor establishing a P2P group. Message(s) 1a are communicated betweensecond UE (“George”) 106 and second ProSe server (B) 142 to enablesecond UE 106 to be registered for proximity services through secondProSe server 142. Similarly, message(s) 1b are communicated betweenfirst UE (“Adam”) 104 and first server (A) 122 to enable first UE 104 tobe registered for proximity services through first server (A) 122.Message(s)/signals 2 are exchanged between first UE 104 and second UE106 to enable first UE 104 and second UE 106 to discover each other.First UE 104 sends message(s) 3a to first IMS server (A) 124. Inparticular, first UE 104 sends an IMS session request which istransmitted as an SIP Invite which includes a Session DescriptionProtocol (SDP) offer that contains the current IP address over LTE forfirst UE 104. In one implementation, the SDP offer contains the currentIP address over LTE in the “c=” (data field) line. The SIP Invite alsoincludes a “ProSe Indication” which indicates that second UE 106 (i.e.,the target user (George)) is in close proximity with first UE 104 (i.e.,the requesting user (Adam)) and that the session could use a directuser-plane between UE-A and UE-B. Based on the ProSe Indication, firstIMS Server 124 (e.g., providing a Serving Call Session Control Function(S-CSCF)) forwards the SIP Invite (i.e., message 3b) to first ProSeServer 122, which, in this case, is an IMS Application Server.

First ProSe Server 122 decides that, since first UE 104 and second UE106 are in close proximity of each other, the requested session shouldbe established with a direct user-plane between first UE 104 and secondUE 106. Thus, first ProSe Server 122 triggers the Network-Initiated P2PGroup Formation procedure (described using FIG. 3), and which includessending message(s) 4 in order for first UE 104 and second UE 106 to forma P2P group and enable first UE 104 and second UE 106 for directcommunication. During the Network-Initiated P2P Group Formationprocedure, first UE 104 and second UE 106 activate respective WiFiinterfaces in WiFi Direct mode (i.e., a selected close rangecommunication technology) and are assigned IP addresses.

However, first ProSe Server 122 establishes the P2P group withoutinitially enabling the direct user-plane which provides a directcommunication session between first UE 104 and second UE 106. When theP2P group is successfully set up, first ProSe Server 122 becomes awareof the new IP addresses assigned to first UE 104 and second UE 106 forWiFi Direct. In one embodiment, first server 122 assigns P2P IPaddresses for WiFi Direct to both first UE 104 and second UE 106. Inanother embodiment, first UE 104 assigns the P2P IP address for WiFiDirect. First ProSe Server 122 responds to the IMS session request sentby first UE 104 by requesting that first UE 104 send another IMS sessionrequest using alternative contact information (i.e., the assigned P2P IPaddresses) to allow the communication session to be enabled. Forexample, first server 122 responds with a message (e.g., in oneimplementation, a “503 Server Unavailable” message as messages 5a and5b) to indicate that the communication session was not established andto instruct first UE 104 to send another IMS session request using theassigned P2P IP addresses. In one embodiment, first UE 104 sends asecond IMS session request by using a new SIP header, such as a“Retry-with-Alternative-Contact” header, that includes the IP addressesassigned to first UE 104 and second UE 106 for WiFi direct.

First UE 104 sends to second UE 106 via first server 122 an SIP Invite(via message 6a) which now contains in SDP the P2P IP address (in “c=”line) assigned to first UE 104. First UE 104 will use this address formedia communication over WiFi direct. In order to require that second UE106 use a corresponding WiFi direct interface for media communication,first UE 104 includes a new Required-Address header that contains theP2P IP address assigned to second UE 106. First server 122 forwards tosecond UE 106 the SIP Invite that includes the new Required-Addressheader with the P2P IP address assigned to second UE 106. Based onreceipt of the P2P IP address provided via the new Required-Addressheader to second UE 106, second UE 106 accepts the SIP Invite by sendingan “OK” response (via message 6b) that contains an SDP which includesthe P2P IP address assigned to second UE 106. As illustrated bymessage(s) 7, based on the assigned P2P IP addresses, first UE 104 andsecond UE 106 establish a user-plane that provides a directcommunication session over WiFi Direct.

FIG. 5 illustrates a third messaging sequence used to establish a P2Pgroup and enable a P2P communication session, according to oneembodiment. Message sequence 500 illustrates a device initiated requestfor establishing a P2P group. Message(s) 1a are communicated betweensecond UE (“George”) 106 and second server (B) 142 to enable second UE106 to be registered for proximity services through second server 142.Similarly, message(s) 1b are communicated between first UE (“Adam”) 104and first server (A) 122 to enable first UE (“Adam”) 104 to beregistered for proximity services through first server 122.Message(s)/signals 2 are exchanged between first UE 104 and second UE106 to enable first UE 104 and second UE 106 to discover each other.First UE 104 sends message(s) 3 to first server (A) 122. In particular,first UE 104 sends a service request that contains the current IPaddress over LTE for first UE 104. The service request includes a “ProSeIndication” which indicates that second UE 106 (i.e., the target user(George)) is in close proximity with first UE 104 (i.e., the requestinguser (Adam)) and that the session could use a direct user-plane betweenUE-A and UE-B.

Based on the ProSe Indication, first ProSe Server 122 decides that,since first UE 104 and second UE 106 are in close proximity of eachother, the requested session should be established with a directuser-plane between first UE 104 and second UE 106. Thus, first ProSeServer 122 triggers the Network-Initiated P2P Group Formation procedure(described using FIG. 3), and which includes sending message(s) 4, inorder for first UE 104 and second UE 106 to form a P2P group and enablefirst UE 104 and second UE 106 for direct communication. During theNetwork-Initiated P2P Group Formation procedure, first UE 104 and secondUE 106 activate respective WiFi interfaces in WiFi Direct mode (i.e., aselected close range communication technology) and are assigned IPaddresses.

However, first ProSe Server 122 establishes the P2P group withoutinitially enabling the direct user-plane which provides a directcommunication session between first UE 104 and second UE 106. When theP2P group is successfully setup, first ProSe Server 122 becomes aware ofthe new IP addresses assigned to first UE 104 and second UE 106 for WiFiDirect. In one embodiment, first server 122 assigns P2P IP addresses forWiFi Direct to both first UE 104 and second UE 106. In anotherembodiment, first UE 104 assigns the P2P IP address for WiFi Direct.

First ProSe Server 122 responds (via message 5) to the service requestsent by first UE 104 by notifying first UE 104 that the P2P group hasbeen established and requesting that first UE 104 transmits acommunication session request to second UE 106 to instruct second UE 106to use an assigned second P2P IP address for P2P communication.

First UE 104 sends to second UE 106 via first server 122 an SIP Invite(via message 6a) which now contains in SDP the P2P IP address assignedto first UE 104. First UE 104 will use this address for mediacommunication over WiFi direct. In order to require that second UE 106use a corresponding WiFi direct interface for media communication, firstUE 104 includes a new Required-Address header that contains the P2P IPaddress assigned to second UE 106. Based on receipt of the P2P IPaddress provided via the new Required-Address header to second UE 106,second UE 106 accepts the SIP Invite by sending an “OK” response (viamessage 6b) that contains an SDP which includes the P2P IP addressassigned to second UE 106. As illustrated by message(s) 7, based on theassigned P2P IP addresses, first UE 104 and second UE 106 establish auser-plane that provides a direct communication session over WiFiDirect.

FIG. 6 illustrates a fourth messaging sequence used to establish a P2Pgroup and enable a P2P communication session, according to oneembodiment. Message sequence 600 illustrates a device initiated requestfor establishing a P2P group. Message(s) 1a are communicated betweensecond UE (“George”) 106 and second server (B) 142 to enable second UE106 to be registered for proximity services through second server 142.Similarly, message(s) 1b are communicated between first UE (“Adam”) 104and first server (A) 122 to enable first UE 104 to be registered forproximity services through first server 122. Message(s)/signals 2 areexchanged between first UE 104 and second UE 106 to enable first UE 104and second UE 106 to discover each other. First UE 104 sends message(s)3a to first IMS server (A) 124. In particular, first UE 104 sends an IMSsession request which is transmitted as an SIP Invite which includes aSession Description Protocol (SDP) offer that contains the current IPaddress over LTE for first UE 104. In one implementation, the SDP offercontains the current IP address over LTE in the “c=” (data field) line.The SIP Invite also includes a “ProSe Indication” which indicates thatsecond UE 106 (i.e., the target user (George)) is in close proximitywith first UE 104 (i.e., the requesting user (Adam)) and that thesession could use a direct user-plane between UE-A and UE-B. Based onthe ProSe Indication, first IMS Server 124 (e.g., providing a ServingCall Session Control Function (S-CSCF)) forwards the SIP Invite (i.e.,message 3b) to first ProSe Server 122, which, in this case, is an IMSApplication Server.

First ProSe Server 122 decides that, since first UE 104 and second UE106 are in close proximity of each other, the requested session shouldbe established with a direct user-plane between first UE 104 and secondUE 106. Thus, first ProSe Server 122 triggers the Network-Initiated P2PGroup Formation procedure (described using FIG. 3), and which includessending message(s) 4 in order for first UE 104 and second UE 106 to forma P2P group and enable first UE 104 and second UE 106 for directcommunication. During the Network-Initiated P2P Group Formationprocedure, first UE 104 and second UE 106 activate respective WiFiinterfaces in WiFi Direct mode (i.e., a selected close rangecommunication technology) and are assigned IP addresses.

However, first ProSe Server 122 establishes the P2P group withoutinitially enabling the direct user-plane which provides a directcommunication session between first UE 104 and second UE 106. When theP2P group is successfully setup, first ProSe Server 122 becomes aware ofthe new IP addresses assigned to first UE 104 and second UE 106 for WiFiDirect. In one embodiment, first ProSe Server 122 assigns P2P IPaddresses for WiFi Direct to both first UE 104 and second UE 106. Inanother embodiment, first UE 104 assigns the P2P IP address for WiFiDirect.

Following establishment of the P2P group and in response to receipt ofthe IMS session request message previously sent by first UE 104, firstProSe Server 122 sends to first UE 104 a response (via messages 5a and5b) which notifies first UE 104 that the P2P group was established butthe communication session was not enabled. In one implementation,messages 5a and 5b are “503 Server Unavailable” messages. First server122 sends a first individual communication session request (via message6a) instructing first UE 104 to use a first assigned IP address forcommunicating within the P2P group. In addition, first server 122 sendsa second communication session request (via message 6b) to second UE 106instructing second UE 106 to use a second assigned IP address forcommunicating within the P2P group.

In order to require that first UE 104 and second UE 106 use respectiveWiFi direct interfaces for media communication, first ProSe Server 122respectively includes within messages 6a and 6b a new Required-Addressheader that contains the P2P IP addresses assigned to first UE 104 andsecond UE 106.

Based on receipt of the P2P IP addresses provided via the newRequired-Address header to first UE 104 and second UE 106, first UE 104and second UE 106 respectively send “OK” responses (via messages 6c)which contain SDP which includes the P2P IP addresses assigned to firstUE 104 and second UE 106. In response to receipt of the “OK” responses,first server 122 respectively enables individual communication sessionsfor first UE 104 and second UE 106. As illustrated by message(s) 7,based on the assigned P2P IP addresses, first UE 104 and second UE 106establish a user-plane that provides a direct communication session overWiFi Direct. In particular, in one embodiment, first ProSe Server 122provides the communication session between first UE 104 and second UE106 by linking the individual communication sessions.

FIGS. 7-10 are flow charts illustrating embodiments of the method bywhich the above processes of the illustrative embodiments can beimplemented. Specifically, FIG. 7 illustrates a first method forestablishing a P2P group and enabling a P2P communication sessionbetween wireless communication devices within the P2P group. FIG. 8illustrates a second method for establishing a P2P group and enabling aP2P communication session. FIG. 9 illustrates a third method forestablishing a P2P group and enabling a P2P communication session. FIG.10 illustrates a fourth method for establishing a P2P group and enablinga P2P communication session. Although the method illustrated by FIGS.7-10 may be described with reference to components and functionalityillustrated by and described in reference to FIGS. 1-6, it should beunderstood that this is merely for convenience and alternativecomponents and/or configurations thereof can be employed whenimplementing the method. Certain portions of the methods may becompleted by GSU utility 216 executing on one or more processors(processor 202) within first ProSe Server 122 (FIGS. 1 and 2). Theexecuted processes then control specific operations of or on first ProSeServer 122 and first controlling network 110. For simplicity isdescribing the method, all method processes are described from theperspective of first server 110 and P2P group setup utility 216.

The method of FIG. 7 begins at initiator block 701 and proceeds to block702 at which GSU utility 216 transmits a first request for establishinga P2P group to first UE 104 which is communicatively coupled to firstcontrolling network 110. At block 704, GSU utility 216 receives fromfirst UE 104 a response that contains operating parameters for the P2Pgroup including an identifier (ID) of a preferred wireless operatingchannel and P2P IP addresses respectively allocated to first UE 104 andsecond UE 106 for use within the P2P group. At block 706, GSU utility216 transmits to second UE 106 coupled to second controlling network 130a request containing (a) information about operating parameters and (b)the ID of the preferred wireless channel. At block 708, GSU utility 216establishes the P2P group using the P2P operating parameters includingthe preferred wireless channel and designates first UE 104 as the GOoperating as the access point for the P2P group. At block 710, GSUutility 216 enables a direct communication session between first UE 104and second UE 106 within P2P group 102. The process ends at block 712.

The method of FIG. 8 begins at initiator block 801 and proceeds to block802 at which GSU utility 216 receives from first UE 104 a first IMSrequest message containing an IP address of first UE 104 on firstcontrolling network 110. At block 804, GSU utility 216 establishes a P2Pgroup for first UE 104 and second UE 106 without enabling a P2Pcommunication session. At block 806, GSU utility 216 provides a responsethat (a) notifies first UE 104 that a P2P communication session was notenabled and (b) instructs first UE 104 to submit second IMS requestmessage that contains the assigned P2P IP addresses. At block 808, GSUutility 216 enables a P2P communication session between first UE 104 andsecond UE 106 within P2P group in response to receipt of the second IMSrequest message. The process ends at block 810.

The method of FIG. 9 begins at initiator block 901 and proceeds to block902 at which GSU utility 216 receives from first UE 104 a first IMSrequest message containing an IP address of first UE 104 on firstcontrolling network 110. In addition, the first IMS request messageindicates that at least one other UE including second UE 106 is in closeproximity with first UE 104. At block 904, based on the close proximitybetween the UEs, GSU utility 216 establishes a P2P group for first UE104 and second UE 106 without enabling a P2P communication session. Atblock 906, GSU utility 216 identifies or assigns respective P2P InternetProtocol (IP) addresses to/for the UEs within the established P2P group.At block 908, GSU utility 216 provides individual first and secondrequest messages to first UE 104 and second UE 106 instructing thesedevices to communicate using P2P IP addresses assigned to first UE 104and second UE 106. At block 910, in response first server 122 receivingrespective messages indicating that first UE 104 and second UE 106accept the individual first and second request messages, GSU utility 216initiates individual communication sessions for first UE 104 and secondUE 106. At block 912, GSU utility 216 links the individual communicationsessions associated with individual first and second requests to enablea P2P communication session between first UE 104 and second UE 106. Theprocess ends at block 914.

The method of FIG. 10 begins at initiator block 1001 and proceeds toblock 1002 at which GSU utility 216 receives from first UE 104 a firstcommunication request message requesting establishment of a P2P groupfor first UE 104 and second UE 106. At block 1004, GSU utility 216establishes a P2P group for first UE 104 and second UE 106. At block1006, GSU utility 216 sends a first response message to first UE 104notifying first UE 104 that the P2P group has been established and of aP2P address assigned to first UE 104 that is to be used for P2Pcommunication. In addition, the response message instructs first UE 104to send an IMS request message to second UE 106 instructing second UE106 to use an IP address assigned to second UE 106 for communicationwithin the established P2P group. At block 1008, in response to firstserver 122 receiving a second response message indicating that second UE106 accept the IMS request message, GSU utility 216 enables a P2Pcommunication session between first UE 104 and second UE 106. Theprocess ends at block 1010.

The flowcharts and block diagrams in the various figures presented anddescribed herein illustrate the architecture, functionality, andoperation of possible implementations of systems, methods and computerprogram products according to various embodiments of the presentdisclosure. In this regard, each block in the flowcharts or blockdiagrams may represent a module, segment, or portion of code, whichcomprises one or more executable instructions for implementing thespecified logical function(s). It should also be noted that, in somealternative implementations, the functions noted in the block may occurout of the order noted in the figures. For example, two blocks shown insuccession may, in fact, be executed substantially concurrently, or theblocks may sometimes be executed in the reverse order, depending uponthe functionality involved. Thus, while the method processes aredescribed and illustrated in a particular sequence, use of a specificsequence of processes is not meant to imply any limitations on thedisclosure. Changes may be made with regards to the sequence ofprocesses without departing from the spirit or scope of the presentdisclosure. Use of a particular sequence is therefore, not to be takenin a limiting sense, and the scope of the present disclosure extends tothe appended claims and equivalents thereof.

In some implementations, certain processes of the methods are combined,performed simultaneously or in a different order, or perhaps omitted,without deviating from the spirit and scope of the disclosure. It willalso be noted that each block of the block diagrams and/or flowchartillustration, and combinations of blocks in the block diagrams and/orflowchart illustration, can be implemented by special purposehardware-based systems that perform the specified functions or acts, orcombinations of special purpose hardware and computer instructions.

While the disclosure has been described with reference to exemplaryembodiments, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the disclosure. Inaddition, many modifications may be made to adapt a particular system,device or component thereof to the teachings of the disclosure withoutdeparting from the essential scope thereof. Therefore, it is intendedthat the disclosure not be limited to the particular embodimentsdisclosed for carrying out this disclosure, but that the disclosure willinclude all embodiments falling within the scope of the appended claims.Moreover, the use of the terms first, second, etc. do not denote anyorder or importance, but rather the terms first, second, etc. are usedto distinguish one element from another.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the disclosure.As used herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

The corresponding structures, materials, acts, and equivalents of allmeans or step plus function elements in the claims below are intended toinclude any structure, material, or act for performing the function incombination with other claimed elements as specifically claimed. Thedescription of the present disclosure has been presented for purposes ofillustration and description, but is not intended to be exhaustive orlimited to the disclosure in the form disclosed. Many modifications andvariations will be apparent to those of ordinary skill in the artwithout departing from the scope and spirit of the disclosure. Theembodiment was chosen and described in order to best explain theprinciples of the disclosure and the practical application, and toenable others of ordinary skill in the art to understand the disclosurefor various embodiments with various modifications as are suited to theparticular use contemplated.

What is claimed is:
 1. A method for establishing a peer to peer (P2P)communication session between a first wireless communication device andat least one other wireless communication device, the method comprising:receiving from the first wireless communication device a communicationrequest message indicating that at least one other wirelesscommunication device is in close proximity with the first wirelesscommunication device; establishing a P2P group which includes the firstwireless communication device and at least one other wirelesscommunication device, based on the close proximity between the wirelesscommunication devices; identifying respective P2P IP addresses for thefirst wireless communication device and the at least one other wirelesscommunication device within the established P2P group; instructing thefirst wireless communication device and the at least one other wirelesscommunication device to communicate within the established P2P groupusing respective P2P IP addresses; and following receipt of a responseindicating acceptance by a second wireless communication device of aninstruction to communicate within the established P2P group using acorresponding P2P IP address, establishing the communication session,wherein said establishing the P2P group further comprises: transmittingfrom a controlling network to the first wireless communication device afirst request for establishing the P2P group, wherein said first requestcontains information about operating parameters for the P2P group;receiving a response from the first wireless communication device thatincludes an identifier (ID) of a preferred wireless channel for the P2Pgroup; transmitting to a second wireless communication device a secondrequest containing (a) the information about the operating parametersand (b) the ID of the preferred wireless channel; designating a selectedwireless communication device from the established P2P group as anaccess point for the P2P group; and wherein the P2P group is establishedusing the operating parameters and the preferred wireless channel, themethod further comprising: retrieving from the communication requestmessage an IP address of the first wireless communication deviceassociated with the controlling network wherein transmitting the firstrequest for establishing the P2P group is triggered in response toreceipt of the communication request message; checking the communicationrequest message for inclusion of a pair of P2P IP addresses to assign toparticipants associated with the received communication request; and inresponse to the received communication request message not including thepair of P2P IP addresses, setting up the P2P group without enabling aP2P communication session.
 2. The method of claim 1, wherein thecommunication request message is a first-type communication requestmessage for enabling the P2P communication session and the methodfurther comprises: in response to receipt of the first-type requestmessage: sending, to the first wireless communication device, a firstindividual communication session request including a first assigned IPaddress and instructing the first wireless communication device to usethe first assigned IP address for communicating within the P2P group;and sending, to the second wireless communication device, a secondcommunication session request including a second assigned IP address andinstructing the second wireless communication device to use the secondassigned IP address for communicating within the P2P group; andfollowing transmission of the individual communication requests:respectively enabling individual communication sessions for the firstand second wireless communication devices; and providing thecommunication session between the first and second wirelesscommunication devices by linking the individual communication sessions.3. The method of claim 1, wherein the operating parameters include atleast one of: (a) a close range communication technology to be used forthe P2P group; (b) a P2P group identity; (c) P2P group securityinformation; and (d) P2P IP address information for wirelesscommunication devices that are included within the P2P group.
 4. Themethod of claim 1, wherein the first wireless communication device iscommunicatively coupled to a first controlling network and the secondwireless communication device is communicatively coupled to a secondcontrolling network that is different from the first controllingnetwork, and the method further comprises: triggering an establishmentof the P2P group and initiating the communication session by routingmessages that are communicated between a first server in the firstcontrolling network and the second wireless communication device via asecond server in the second controlling network at which the seconddevice is registered, wherein the second wireless communication deviceis triggered to initiate operation as a P2P client and search for awireless communication device operating as the access point thatsupports the operating parameters, in order to enable a P2Pcommunication session.
 5. The method of claim 1, wherein thecommunication request message is a first-type request message forenabling the P2P communication session and the method further comprises:in response to receipt of the first-type request message, providing aresponse message that (a) notifies the first wireless communicationdevice that the P2P communication session was not enabled and (b)instructs the first wireless communication device to submit a secondcommunication request message that contains respectively assigned IPaddresses associated with the established P2P group; and in response tosubsequently receiving the second communication request message,enabling said P2P communication session using the respectively assignedIP addresses.
 6. The method of claim 1, wherein the communicationrequest message is a second-type request message requesting the P2Pgroup be established, and the method further comprises: in response toreceipt of the second-type request message: notifying said firstwireless communication device that the P2P group has been established;and instructing the first wireless communication device to use anassigned first P2P IP address for P2P communication; in response to theP2P group being established, triggering the first wireless communicationdevice to transmit a communication session request to the secondwireless communication device that instructs the second wirelesscommunication device to use an assigned second P2P IP address for P2Pcommunication; and enabling the communication session for the P2P groupusing the assigned first P2P IP address for the first wirelesscommunication device and the assigned second P2P IP address for thesecond wireless communication device.
 7. The method of claim 1, whereinthe communication request message received from the first wirelesscommunication device is an Internet Protocol Multimedia Subsystem (IMS)session request message transmitted as a Session Initiation Protocol(SIP) invite.
 8. The method of claim 1, wherein: the first communicationdevice sends the communication session request message in response todiscovering the second communication device via one of: (a) WiFi Direct,(b) Long Term Evolution (LTE) Direct, (c) Bluetooth and (d) anotherclose range communication technology.
 9. A data processing system (DPS)communicatively coupled to a first wireless communication device andoperating as a first proximity services server within a controllingnetwork and which includes: at least one processor; at least one memorysystem; and a group set-up utility which when executed on the at leastone processor: receives from the first wireless communication device acommunication request message indicating that at least one otherwireless communication device is in close proximity with the firstwireless communication device; establishes a P2P group which includesthe first wireless communication device and at least one other wirelesscommunication device, based on the close proximity between the wirelesscommunication devices; identifies respective P2P IP addresses for thefirst wireless communication device and the at least one other wirelesscommunication device within the established P2P group; instructs thefirst wireless communication device and the at least one other wirelesscommunication device to communicate within the established P2P groupusing respective P2P IP addresses; and following receipt of a responseindicating acceptance by a second wireless communication device of aninstruction to communicate within the established P2P group using acorresponding P2P IP address, establishes the communication session,wherein the DPS establishes the P2P group by: transmitting from acontrolling network to the first wireless communication device a firstrequest for establishing the P2P group, wherein said first requestcontains information about operating parameters for the P2P group;receiving a response from the first wireless communication device thatincludes an identifier (ID) of a preferred wireless channel for the P2Pgroup; transmitting to a second wireless communication device a secondrequest containing (a) the information about the operating parametersand (b) the ID of the preferred wireless channel; designating a selectedwireless communication device from the established P2P group as anaccess point for the P2P group; and wherein the P2P group is establishedusing the operating parameters and the preferred wireless channel,wherein the DPS: retrieves from the communication request message an IPaddress of the first wireless communication device associated with thecontrolling network, wherein transmitting the first request forestablishing the P2P group is triggered in response to receipt of thecommunication request message; checks the communication request messagefor inclusion of a pair of P2P IP addresses to assign to participantsassociated with the received communication request; and in response tothe received communication request message not including the pair of P2PIP addresses, setting up the P2P group without enabling a P2Pcommunication session.
 10. The DPS of claim 9, wherein the communicationrequest message is a first-type communication request message forenabling the P2P communication session and wherein the DPS: in responseto receipt of the first-type request message: sends, to the firstwireless communication device, a first individual communication sessionrequest including a first assigned IP address and instructing the firstwireless communication device to use the first assigned IP address forcommunicating within the P2P group; and sends, to the second wirelesscommunication device, a second communication session request including asecond assigned IP address and instructing the second wirelesscommunication device to use the second assigned IP address forcommunicating within the P2P group; and following transmission of theindividual communication requests: respectively enables individualcommunication sessions for the first and second wireless communicationdevices; and provides the communication session between the first andsecond wireless communication devices by linking the individualcommunication sessions.
 11. The DPS of claim 9, wherein the operatingparameters include at least one of: (a) a close range communicationtechnology to be used for the P2P group; (b) a P2P group identity; (c)P2P group security information; and (d) P2P IP address information forwireless communication devices that are included within the P2P group.12. The DPS of claim 9, wherein: the first wireless communication deviceis communicatively coupled to a first controlling network, the secondwireless communication device is communicatively coupled to a secondcontrolling network that is different from the first controllingnetwork; and the DPS triggers an establishment of the P2P group andinitiates the communication session by routing messages that arecommunicated between a first proximity services server in the firstcontrolling network and the second wireless communication device via asecond proximity services server in the second controlling network atwhich the second device is registered, wherein the second wirelesscommunication device is triggered to initiate operation as a P2P clientand search for a wireless communication device operating as the accesspoint that supports the operating parameters, in order to enable a P2Pcommunication session.
 13. The DPS of claim 9, wherein the communicationrequest message is a first-type request message for enabling the P2Pcommunication session, and the DPS: in response to receipt of thefirst-type request message, provides a response message that (a)notifies the first wireless communication device that the P2Pcommunication session was not enabled and (b) instructs the firstwireless communication device to submit a second communication requestmessage that contains respectively assigned IP addresses associated withthe established P2P group; and in response to subsequently receiving thesecond communication request message, enables said P2P communicationsession using the respectively assigned IP addresses.
 14. The DPS ofclaim 9, wherein the communication request message is a second-typerequest message requesting the P2P group be established, and the DPS: inresponse to receipt of the second-type request message: notifies saidfirst wireless communication device that the P2P group has beenestablished; and instructs the first wireless communication device touse an assigned first P2P IP address for P2P communication; in responseto the P2P group being established, triggers the first wirelesscommunication device to transmit a communication session request to thesecond wireless communication device that instructs the second wirelesscommunication device to use an assigned second P2P IP address for P2Pcommunication; and enables the communication session for the P2P groupusing the assigned first P2P IP address for the first wirelesscommunication device and the assigned second P2P IP address for thesecond wireless communication device.